Steam-generating plant



Nov. 17 1925- 1,561,546 J. E. KENNEDY STEAM GENERATING PLANT Filed Oct. 13 1924 3 Sheets-Sheet l Nov. 17 1925. 1,561,546

J. E. KENNEDY STEAM GENERATING PLANT 3 Sheets-Sheet 2 skilled inthe art to which itappertains to Patented Nov. 17, 19 25.

UNITED s'rAr-ES i a-raur OFFICE.

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(llamas med amber 1: 1924. Serial No. 743,380.

' plant employing ba asse, orv similar moist similar. moist and bu and bulky fuels an has for its objects the association of the steam boiler section and a furnace section soconstructed and ar ranged as to affect a maximum eificiency in the'combustion of the fuel and in-the uantity of steam generated per unitweig t of fuel employed, within a comparatively wide range of operativerequirements for steam, as, or example, in the operation of su ar making plants, the generating plant bei sufiiciently flexible to take care of deman s put upon it rangin from arelatively hea overloadto a loa requiring only a sma proportion of the normal capacity of the plant, without sacrificing the lmportant elements of efiiciency and economy.

.panying drawings, in which v Fig.1 is a front' elevation, partly in sectilon, on' the line 1-1 of Fig. 2, of the pant. I j v N Fig. 2is .a sectional plan view on the line 2+2 of Fig.3;

" Fig.3 is a vertical longitudinal sectional elevation on the line 3 3 of Fig. 2.

Various types and constructional forms of steam generators em loyin 'bagasse'and fue s-ha ve been proposed and I installed, heretofore, primarilyffor. thepurpose' of utilizing the bagasseandlike materials, which have proven troublesome waste products in the industries, for the fuel values thereof, but practically all of the former installations have provenamore' or less unsatisfactory, becauseof'th'e diflicultyin effecting complete combustion of the moist fuel and a concomitant difficulty of delivering the products of. combustion to the boiler unit, -s o distributed tion with the boiler section. The invention'is illustrated in the accomas to effect maximum, efficiency in the generation of steam. A further objection to the former t of bagasse burnin (naces employla gas heatin units to oiler plants is the practical inabllit to accurately vregulate the steam generate to the needs of the mechanism in which the steam is; employed, as, for example, in sugar boiling I plants and the like, because of the fact-fthat the furnaces of the steam generating plants are designed primarily to operateon a iven load and are wholly lacking in flexi ility to accommodate overloads or underloads. The instant invention involves a coordination of the boilerand furnace units; that willcorrect all of these objections and difficulties and rovide a furnace unit, having suflicient flexibility of operation to enable fur-V the steam generating lant as a whole to be worked under con 'tions of'maximumv efiiciency and economy notonly when the. plant is worked at normal capacity, but also under sudden demands requiring an overproduction of steam, and, conversely, when the plant is operatedat a subnormal load.

These desirable objects are obtained by the v a particular: construction of the various. units constituting the furnace section of the plant and t e coordination of said furnace-sec A re resents e an B the Referring to ,the drawings, the boiler section as a w 01 furnace section. a The boiler section preferably comprises the usual installation of a water tube boiler, the particular boiler ila lustrated in the fragmentary view in the drawin bein of the well known Sterling type, w ich is oused inthe usual masonry structure reinforced b ,beams and irders, as will 'be'understood by vthose sk led in the art. The boilerhousing is graphically represented inthe drawings-as Involving a front wall 1, arear wall 2: and side walls 3 and-4.; The boiler. unit, represented by the numeral 6, includes the usual mud drum and theinclined tubes connectin the latter with the top structure of the "Oiler and interposed in-the course of the products ofcombustion from the furnace sectiom hThe usual transverse firewall 5 isidisposed in the boiler section. toprotect the mud drum- I from direct contact with the hot'products of combustion. It will beunderstood that the boiler section is provided with the usual structural and operative elements common to boilers of this type.

The furnace section B which is disposed in advance of the boiler section A is of considerable greater width than the boiler section and comprisesv a front wall 10, side walls 11 and 12 parallel with the longitudinal axis of the wall structure and converging side Walls 11 and 12', which connect the parallel side Walls 11 and 12 with the side walls 3 and 4, respectively of the boiler section. Extending longitudinally of the furnace section and throughout the length of the latter is a division wall 13, which divides the furnace section- 7 into halves and each half furnace section is subdivided by agenerally longitudinal vertical wall, the rear portion'of which is deflected toward the central wall, one of spanning the spaces between the side walls of the boiler section A and the extension of the central wall 13 beyond the ends of the subdivision walls 14 and 15 are. arched crowns and 21, the inner ends of the respective crowns being inclined downwardly, as at 20 and 21, to serve as reverberatory deflectors for the products of com-' bustion and to direct said products onto the lower portions of the water tubes of the-boiler.

Disposed transversely of the furnace section and extending longitudinally thereof from the grate sections to the inner limits of the arches 20 and 21 is a generally archshaped fire bridge at the highest point 30 of which the division walls 14 and .15 terminate.- :By this construction, there are provided four separate grate and combustion chambers which provide relatively large initial chambers to receive the bagasse'and in which preliminary drying and complete combustion of the fuel may be effected, the products of combustion passing upward from the grate chambers ,be-

ing deflected by the wall sections 11, 14!, 15 and 12' toward the central wall 13, the products from the two grates in each half of the furnace being delivered and commin led in the discharge sections of the com ustion chambers lying on either side of the central wall 13, and the products of combustion from the grates in both halves-of the furnace bein commmgled beyond the inner end of t e central wall 13 and directed downwardly by the inclined crowns 20 and 21' onto the lower sections of the boiler tubes, and meeting the bridge 30 and associated with each flat grate section is a relatively steep stepladder grate 32 extending from the forward portion of the flat grate to the front wall 10 of the furnace chamben' Located above each of the stepladder grates 32 is a fuel feedopening 25, which extends through the top o the furnace section and communicates with any suitable type of feeding mechanism 26 for delivering the bagasse or similar fuel to the furnace, the feed opening and chute being defined by the front wall of the furnace and a curtain arch 22 extending downwardly from. the top of the furnace to a point above the stepladder grate. The front wall of each furnace section is provided with the usual stoke opening 27 and ash pit opening 28 provided with suitable closures. Preferably'the stepladder grates are blanked off for the greater part of their area in order to prevent setting up back drafts and to insure that the supply of the combustion supporting air passes upward through the fuel on the flat grates 31.

The function of the stepladder grates is primarily to provide for a preliminary drying of the bagasse, or similar fuel, before the latter is delivered onto the flat grates where combustion is effected. If

conditions are met when this preliminary drying is found to be unnecessary, obviously, the stepladder grates may be dispensed with and the bagasse delivered directly to the flat grates.

In' the normal operation of the apparatus as described, the bagasse, or similar fuel, is fed in through the chutes 25 in properly regulated quantities directly onto the inclined stepladder grates 32, down which the fuel passes slowly and is ultimately discharged onto the flat grates 31. During the passage of the bagasse over the steplad-' der "grates, the products of combustion of the bagasse being burned on the flat grates pass upwardly over the bagasse onthe ste ladder grates and take up the moisture 1n the bagasse, so that the latter is delivered to the flat grates in proper condition to effect combustion, which latter condition may be assured by a properly regulated supply of air by any of the well known means usually employed for this purpose and which are so well understood as to'require no specific illustration. The combustion initiated inythe fuel on the flat grates is com-- pleted as the aseous roducts rise and pass .5 over the bri ge .wa an intimate admixtureof the air bein assured by the con striction of the com ustion spaces defined by the arched fire bridge30 and the rela-- tively converging walls of the combustion '10 chambers, the combustion products from the two sets of chambers constituting each half of the furnace section commingling in the common discharge chamber of each half secxtion defined by the central wall '13, the side 1 walls 3 and 40f the boiler section and the v 'the central wall 13 downwardly inclined-crowns and 21' and the products from all ofthe combus-- tion chambers being; commingled in the initial portion ofthe boiler section beyond and the bridge wall and the crowns 20-and 21'.

' From the foregoing, it will be. apparent that, when the steam generating system is operating under normal" capacity, all four 25 6 the gratesections will be supplied with properly regulated amounts of bagasse, and, when extraordinary demands are put 'upon the generator, in case of overload, a relative- 1y larger proportion of fuel and air will be portion of the flat ,fed to the several. gr'ate and combustion,

I the feed of the fuel to one or more of the 0 ample grate area'for grates may" be suspended, and, if desired, the particular grate or'grates not' receiving fuel may be blanked ofi bycjovering the 'surface thereof with bricks,'or the like. In any event, however" the grate andcombustion chambers which eration will effect a thorough and com late the products of combustion from both halves of the "furnace section into the boiler section to roduce'a thorough commin ling of the re ucts of combustion and the int:- y I the same against the lower ends of the boiler tubes, as hereinbefore explained. It has been found'that the furnace, as described, maintains its efliciencyand econom v whether two, three or four of the grate sec-" operation, l practically ummpaire tions are operated, provided the operated grates are located on 'o central wall 13. It will seen,ither efore, that the installation,

any conditions of 3peration, insures complete combustion of e fuel under all conditlo-ns of operation, facilitates the, economical production of the amount of steam desired without impairing 5 the efficiency of the steam generation and en- I having arched crowns,

bers to the discharge tween the chambers of each are maintained in op- "deflected laterallyrtoward the L5 combustion of the fuel fed thereto and direct site sides of the as described, provides ables the plant to be operated to meet any required conditions of steam generation from a relatively high overload to a .load comparatively far below normal without material loss in either efiiciency or economy.

1 What Ielaim iszf H, v i

1. A steam generating plant employing ba'g'asse or similar fuel, comprising a boiler nace section of greater width than the boiler section and connected therewith by converging side walls, said furnace- Section including two pairs of grate and combustion chambers divided by a longitudinal. wall and I an arched fire bridge extending substantially from the grate charm ends of the combus tion chambers, the dividing wall between the pairs of chambers extendm throughout the length of t e furnace section and the dividing walls between ,the

chambers of each pair terminating approximafiely' at the-highest pointof theb ridge Wa 2 A steam enerating plant employing bagasse 'or'simi ar fuel, comprising a boiler section having a boiler therein, and a furnace section of greater wldth than the boiler section and connected therewith by conver having i arched crowns, an arched 'fire iextending substantially from the gratg ehambers to the discharge ends of the section having a boiler therein, and a furlongitudinally I ing side walls, said furnace section inclu -ing 'two' pairs of grate and combustion chambers fdivided by a' longitudinal wall and gitudinally throughout the length. of "the I furnace section and thedividing walls be pair terminating approximately at the highest point of the brldge wall, the portions ofthe latter dividing walls which overlie the fire bridge being central wall.

3. A steam generating plant employing bagassefor similar fuel, comprising a boiler sectionhaving a boiler therein, and a furnace .Msection' of greater width than the boiler" section and connected therewith by converging side walls, said furnace section including four ate chambers and four combustion cham ers, a central wall extend- I ing throughout the length of the furnace section dividing the grate chambers and combustion charnhers' into pairsfdivision walls between the grate and combustion chambers of each pair'terminating; short of the inner end of the central walland each having -an end portion deflected toward said central wall, four arched crowns span ning the. the chamber defining sideand division walls, two arched crowns spanning the side walls and the central wall, and an the furnace section a'ndlongitudinallyof I arched fire bridge extending transversely-of the same substantially from the grate chambers to the inner end of the furnace section.

4. A steam generating plant employing bagasse or similar fuel, comprising a boiler section having a boiler therein, and a fur-.

sion walls between the grate and comg bustion chambers of each air terminating short of the inner. en of the central Wall and each having an end portion deflected toward said central wall, four arched crowns spanning the five chamber defining side and division Walls, two arched crowns spanning the side walls and the central wall, an arched fire bridge extending transversely of the furnace section and longitudinally of the same substantially from the grate chambers to the inner end of the furnace section, flat grates near the bottoms of the grate chambers, and steeply inclined stepladder grates disposed between the front Wall of the furnace section and the flat rates.

' In testimony whereof I aflix my signature.

JAMES E. KENNEDY. 

